Characterisation of alkaline tailings from a lead/zinc mine in South Africa and evaluation of their revegetation potential using five indigenous grass species
South African Journal of Plant and Soil
School of Agriculture, Earth and Environmental Sciences, University of KwaZulu-Natal, Private Bag X01, Pietermaritzburg, Scottsville 3209, South Africa; Institute for Commercial Forestry Research, PO Box 100281, Pietermaritzburg, Scottsville 3209, South Africa
Tailings from a lead/zinc (Pb/Zn) mine were characterised and their revegetation potential investigated under glasshouse conditions using five grass species with three rates of inorganic fertiliser. The tailings were alkaline with low nutrient concentrations but high total and extractable Zn. The yield of all grass species increased with an increase in fertiliser rate. The yield of Cenchrus ciliaris at the full fertiliser application rate was significantly higher than the other species tested, followed by Digitaria eriantha. Cymbopogon plurinodis was the third-highest-yielding species, whereas yields of Eragrostis superba and Fingeruthia africana were similar. Concentrations of Zn in the foliage tended to be over the reported grass foliage ranges, whereas Pb concentrations were within typical norms. It is recommended that C. ciliaris, D. eriantha and E. superba be used for initial revegetation, with other species used to improve biodiversity after initial cover has been established. © 2013 Copyright Combined Congress Continuing Committee.
biodiversity; carbonate; concentration (composition); cost-benefit analysis; fertilizer application; foliage; grass; habitat restoration; lead; native species; phytoremediation; restoration ecology; revegetation; tailings; zinc; South Africa